Dissociating neural components of decisions I: summary of Hare et al. 2008

Earlier this year in the Journal of Neuroscience, Hare et al. addressed the question of whether different reward computations and decision variables can be dissociated in the human brain using fMRI. This post is an introduction to the question and the task, and the next post will interpret the results, offer a few critiques, and attempt to connect this economics- and reinforcement learning-based finding to emotion (what we’re all into anyway). In addition to addressing a great question, the paper is also of interest as it is likely to make a decent impression on the field: in addition to the lead author, the ‘et al.’ is composed of rather prominent names: Wolfram Schultz, Colin Camerer, John O’Doherty, and Antonio Rangel.

Prior research has found that the ventral striatum and ventral prefrontal cortex are very involved in tasks that arouse emotion and require decisions about valued stimuli. Some fMRI studies have reported that the ventral striatum, a dopamine-innervated region of the basal gangia (discussed in a prior post), is more active when subjects perceive an error in their reward expectations such as a sudden lottery win. Other work suggests that the same region instead responds to the value of stimuli on the screen, such as how much you like a product. Unfortunately, most previous experiements cannot dissociate value from prediction error.

Cognitive consequences of emotion regulation

This week, I review an article by Devenney and Pizzagalli from a recent issue of Psychophysiology. I’ve divided my review into several sections: an introduction, which briefly summarizes the relevant literature; a review of the ERP method, for readers who aren’t familiar with it; a summary of the authors’ results; and my interpretation of those results.

On the relative independence of Thinking Biases and Cognitive Ability (Stanovich 2008 JPSP)

Abstract:
In 7 different studies, the authors observed that a large number of thinking biases are uncorrelated with cognitive ability. These thinking biases include some of the most classic and well-studied biases in the heuristics and biases literature, including the conjunction effect, framing effects, anchoring effects, outcome bias, base-rate neglect, “less is more” effects, affect biases, omission bias, myside bias, sunk-cost effect, and certainty effects that violate the axioms of expected utility theory. In a further experiment, the authors nonetheless showed that cognitive ability does correlate with the tendency to avoid some rational thinking biases, specifically the tendency to display denominator neglect, probability matching rather than maximizing, belief bias, and matching bias on the 4-card selection task. The authors present a framework for predicting when cognitive ability will and will not correlate with a rational thinking tendency.

Three nice things about this paper:

Do we need a domain-specific process for affective maintenance?

The original working memory model proposed by Baddeley and Hitch doesn’t explicitly account for how affective information is temporarily maintained. According to Mikels et al. (2008), relatively few studies have examined how affective information is held in working memory. The main reason is probably that it is unclear what it means to maintain affective information temporarily. According to the authors, maintenance of affective information means holding subjective affective information (see Watanabe et al, 2007 for an alternative and more detailed definition).

Throughout this study, the participants are presented with two pictures sequentially. Depending on task requirements, they either need to memorize the brightness of the first image or their feelings towards the first image. Their task is always to report whether the second image is more or less intense than the first along the encoded dimension. The authors categorized trials based on this dimension (brightness or affect) and whether the two images were near or far from each other on a normative scale. Below are some of my thoughts on the study’s methodology.  [For a more detailed explanation of the design, see Amitai's introduction]

Don’t stop…hold[ing] on to that feeling!

A Brief Introduction to Mikels et al., 2008

Anyone who learned about memory even briefly in an Intro Psych course (since the 70’s) is likely to have heard about the concept of a “working memory,” a system that holds things in our minds for a brief period of time. When Baddeley & Hitch proposed the model it came ready with a storage buffer for verbal information (the phonological loop) and for graphic information (the visuospatial sketchpad). One of the great experimental thrusts of these proposed separable components has been to allow researchers to selectively interfere with one buffer or the other with an appropriate task, and see whether one form of interference selectively impairs performance on the task of interest (suggesting a role for that component in task performance).

While Baddeley has since proposed adding an ‘episodic buffer’ to the model, Mikels et al. (2008) argue that more attention ought to be paid to the question of whether and/or how it is that we hold a feeling in memory over brief periods. In the paper reviewed below, Mikels and colleagues suggest that there may in fact be a separate component of working memory dedicated to affective information, and they provide putative evidence for this being the case. I will briefly introduce their methods and results, followed by Yang-Ming’s critical analysis thereof.

What is the Delgado paper really telling us? A skeptical view

My most salient impression of the Delgado &al. paper is uncertainty about its significance.  It’s nice that they’ve filled a gap in the literature by showing that positive, and not just negative, conditioned stimuli can be altered by “cognitive regulation.”  But what has really been shown here?

Finances and feelings: Cognition meets emotion at the cash register

Feeling pain at the pump? Dread with the latest drop in the Dow? Or perhaps joy after a jump in your salary?

We speak as though it’s obvious that money and emotions are intricately intertwined. If this is the case, why isn’t the Fed paying more attention to our mental health? Why aren’t clinical psychologists promoting financial security along with emotional well-being? Surprisingly, the research fields of economics and psychology have long ignored this connection, and instead it has been the newly burgeoning field of neuroeconomics that has stepped in to bridge the gap.

Recently, scientists and NYU and Rutgers demonstrated an important new link between finances and feelings.

Joining Bears & Bridges

Welcome to our new reading group! If you’re interested in joining (translation: the ability to post comments and occasional content rather than just lurking), you must sign up.  This comprises two steps:
1) Get an account on wordpress
2) Send me or Amitai the email address you used to sign up

Don’t forget to send us feedback on reading & presentation requests! We’re trying to divide the labor of reading list development as much as possible, and this also gives us a sense of what other people are interested in.

Note: Signing up does not commit you to anything, in terms of posting responsibilities. It merely gives us a guideline for who to contact from time to time about presenting.